Cabinet shelf elevator and control



Dec. 10, 1968 J HAMMOND 3,415,586

CABINET SHELF ELEVATOR AND CONTROL Filed June 12, 1967 2 Sheets-Sheet 1lOu k llo lm/ ll lle l-Ob nwm m INVENTOR. JAMES F. HAMMOND ll BY FIG.2wwfzvy ATTORNEYS Dec. 10, 1968 .1. F. HAMMOND CABINET SHELF ELEVATOR ANDCONTROL Filed June 12, 1967 2 Sheets-Sheet 2 lOb -iiiIInumiiiiiiiilm iilOb I00 FIG.3

INVENTOR. JAMES F. HAMMOND ;ORNEYS M w i a m 4 MN IAAPC. m 5 M a a F9T1- 2i o United States Patent 3,415,586 CABINET SHELF ELEVATOR ANDCONTROL James F. Hammond, 17 Pleasant St., Apt. 1, Los Gatos, Calif.95030 Filed June 12, 1967, Ser. No. 645,343 Claims. (Cl. 312-312)ABSTRACT OF THE DISCLOSURE Cabinet structure provided with an outershell and shelf structure slidably supported in the shell by webs whichare adapted to be wound on a motor driven roller. The motor and anelectromagnetic brake provided thereto are both adapted to be energizedwhen the shelf structure is being raised. Only the electromagnetic brakeis adapted to be energized when the shelf structure is being lowered bygravity. A flexible cable is provided for controlling the double pole.double throw switch which is positioned on the motor casing so that thisswitch may be operated from a remote point to control the raising andlowering of the shelf structure.

This invention relates to cabinet structure provided with a unit forraising and lowering the shelves thereof.

An object of this invention is to provide an improved shelf raising andlowering unit for cabinets such as are used in a home, apartment or thelike so that the upper shelves of the cabinet may be lowered forconvenient access thereto.

Another object of this invention is to provide an improved shelf raisingand lowering device which is adapted to be electrically energized andwhich is provided with a flexible cable for remote operation of thecontrol switch thereof so that the unit may be completely wired and madeavailable as such to cabinet makers who simply attach the mechanicalparts thereof to the cabinet and it is unnecessary for such cabinetmakers to install electric wiring required for the unit to becomeoperative.

Still another object of this invention is to provide an improved cabinetstructure in which the shelves may be raised or lowered and in which theshelf structure is provided with members slidably engaging front railsattached to the outer shell of the cabinet structure which prevents theouter shell from expanding and eliminates the necessity for providingbridging members across the front of the cabinet shell to hold thecabinet shell, particularly the lower front thereof, from abnormallyspreading apart.

Another object of this invention is to provide an improved shelf raisingand lowering unit to cabinets such as are used in the home, apartmentsor the like, said unit being provided 'with webs which are attached tothe opposite sides of the shelf structure, said webs being adapted to bewound on a roller and interleaved during the winding thereof on theroller so that uniform pull is exerted by the roller on both webs,whereby uniform lifting action is provided to the opposite sides of theshelf structure during the raising and lowering thereof.

Other and further objects of this invention will be apparent to thoseskilled in the art to which it relates from the following specification,claims and drawings, in which, briefly:

FIG. 1 is a perspective view of an embodiment of this invention,partially broken away, with the shelf structure shown in solid lines inelevated position, and' in broken lines in lowered position;

FIG. 2 is a sectional view taken along the line 22 of FIG. 1

FIG. 3 is a top view of an embodiment of the shelf raising and loweringapparatus of this invention;

FIG. 4 is a fragmentary view taken along the line 44 of FIG. 3 showingthe upper limit switch; and

FIG. 5 is a diagram of electrical connections employed in thisapparatus.

Referring to the drawing in detail, reference numeral 10 designates theouter shell of a cabinet structure such as is employed in kitchens ofhomes, apartments and the like. This cabinet structure is provided withinwardly extending front rails 10a that are attached to the front edgesof side walls 10b. The rails 10a are each provided with a groove on theinside thereof for receiving the members 11a which are attached to theshelf structure 11.

The shelf structure 11 is provided with several shelves 111), one ofwhich functions as the bottom thereof, and these shelves are attached tothe side walls 11c and back panel 11d. The members 110, which areslidable in the grooves 100, function to restrain the side walls 11bfrom spreading since no bottom member is provided to the outer shell 10.The shelf structure 11 is slidable up and down in the outer shell 10 sothat the shelves 11b thereof may be raised or lowered to provide easyaccess to the upper shelves thereof. :No cross pieces are providedbetween the rails 1011 so that the operators fingers cannot be caughtbetween the shelves 11b and the shell structure 10 during raising orlowering of the shelves.

A shelf 12 is provided in the shell structure 10 near the upper endthereof to form a compartment with the upper portions of the sides 10band back 10d for receiving the shelf elevating and lowering unit 13. Theshelf raising and lowering apparatus 13 is provided with a conventionalfractional horse power motor and speed reducing gearing. An output shaft15 is provided to the reduction gearing and this shaft is rotated at arelatively slow speed of one or two r.p.m. Roller 16 is fixedly attachedto shaft 15. Webs 17 and .18, which may be made of any flexible materialsuch as canvas, having suitable strength, are provided for raising andlowering the shelf structure. One of the ends of each of the webs isattached to the roller 16 so that these webs may be wound on the roller16 when this roller is driven by the motor and speed reduction gearing14. The lower ends of the webs 17 and 18 are attached to the sides 110,as shown for example at 18a. Suitable rollers 19 and 20 are attached tothe respective ends of the shelf or platform 12 and the webs 17 and 18ride over these respective rollers during the raising and lowering ofthe shelf structure .11.

One end of the motor shaft 21 extends outward from the motor housing andis provided with a wheel 22 which is fixedly attached thereto. The wheel22 may be made of suitable plastic material such as nylon, Delrin or thelike. The armature 23 of the electromagnet 24 is adapted to bespring-pressed by a spring 23a against the plastic wheel 22 to preventthe motor shaft 21 and the shaft 15 from turning when the shelfstructure 11 is in elevated position and the motor is deenergized.

The diagram of connections employed in this apparatus is shown in FIG.5. The double pole double throw switch 25 which is mounted on the motorand gear apparatus 14 is remotely controlled by the flexible cable 25a.This cable is positioned in the tube 25b which extends bet-ween thesides 10b and of the cabinet structure, and the lower end thereofextends slightly below the shell 10, as shown in FIG. 1. This lower endis provided with a small knob 250 which is attached to the cable 25a.Thus, the switch 25 may be operated by either pulling or pushing on theknob 250. Two limit switches 26 and 27 are provided to this apparatus.Limit switch 26 is attached to the shelf 12 as shown in FIG. 4 and isprovided with an actuating member 26a which is adapted to be engaged bythe upper edge of the back panel 110! of the shelf structure when thisstructure is in its upper position so that the switch 26 is open. Limitswitch 27 is provided for limitng the downward movement of the shelfstructure and this switch is attached to a bracket that is attached tothe top of the motor and reduction gear unit 14. A cable or cord 27a hasone end thereof attached to the arm of switch 27 and the other endthereof attached to the web 18, as shown in FIG. 3. When the shelfstructure 11 is in its down position web 18 extends the cord 27a, asshown by the broken line in FIG. 3, and switch 27 is opened thereby.

When the blades 28 and 29 of double pole double throw switch 25 are intheir upper position as shown in FIG. 5 in which they make contact withthe upper contacts of the switch, the motor 14a and electromagneticbrake 24 are energized if the shelf structure 11 is in its down positionor partially lowered so that the back panel 11d thereof is clear ofswitch 26 and this switch is closed. The motor and gear arrangement 14then function to drive the roller 16 and wind the webs 17 and 18 thereonto raise the shelf structure 11 until the back panel 11d of thestructure engages the actuating member 26a of the limit switch 26 andopens this switch.

When switch 26 is open, both the motor 14a and the electromagnet winding24 of the brake are de-energized. Armature 23 of the electromagneticbrake is then pressed by the spring 23a against the wheel 22 to preventit and the shaft 21 of the motor from rotating. The shelf structure 11cannot be lowered by gravity as long as the brake engages the wheel 22.When the operator desires to lower the shelf structure 11 from its upposition he pulls down on the button 250 which is attached to cable 25aand shifts the switch blades 28 and 29 of switch 25 to engage the lowercontacts of this switch, as shown in FIG. 5. Only blade 28 is active inthis position, as will be seen from an examination of FIG. 5, and thisblade connects the switch 27 to the one side of the current supply line.Switch 27 is closed when the shelf structure is in its up positioninasmuch as the actuating cable 27a thereof is in relaxed position.Winding 24 of the brake is energized through switch 27 and the armature23 of the brake is retracted from the wheel 22, thus releasing the brakeand allowing the shaft 21 of the motor to rotate. Shelf structure 11 isthen allowed to be lowered by the force of gravity thereon until the web18 is extended and tension applied to the cord 27a, which functions toopen switch 27. Winding 24 of the electromagnetic brake is thende-energized and the armature 23 thereof released so that it is pressedby spring 23a against the wheel 22 which is restrained from furtherrotation. The shelf structure is now in its down position and, in orderto raise it, the operator pushes knob 250 up to move the blades 28 and29 to their up position and connect the motor and brake winding to thecurrent supply through switch 26, and the raising operation described isrepeated.

One of the features of this invention resides in the fact that thisshelf raising apparatus may be provided as a unit which may be installedby cabinet makers and the current supply connection thereto may beplugged into a conventional wall electric outlet. For this purpose theswitch 26 may be attached to the motor unit by a suitable bracket whichalso encloses the wiring to this switch.

While -I have shown a preferred embodiment of this invention, it will beunderstood that the invention is capable of variation and modificationfrom the form shown so that the scope thereof should be limited only bythe proper scope of the claims appended hereto.

What I claim is:

1. In apparatus for raising and lowering the shelves of a cabinet, thecombination of cabinet structure having an outer shell including sidewalls having the rear edges thereof attached to a back panel, and shelfstructure slid- Cit able up and down in said outer shell, said shelfstructure having side walls and a back panel and a plurality of shelvesattached thereto, a pair of webs, means attaching the bottom ends ofsaid webs to the outer sides of said side walls of said shelf structureso that parts of said webs are positioned between the side walls of saidshelf structure and said outer shell, a roller, means including anelectric motor for driving said roller, means attaching the top ends ofsaid webs to said roller, said webs being adapted to be wound on saidroller when said roller is driven by said motor for lifting said shelfstructure in said outer shell, electromagnetic brake means associatedwith said electric motor preventing downward travel of said shelfstructure by force of gravity when said motor is de-energized, switchmeans connecting said motor and said electromagnetic brake to a sourceof current supply to energize said brake and said motor when said shelfstructure is raised, said switch means having means connecting saidbrake only to said source of current supply to energize said brake whensaid shelf structure is lowered by gravity.

2. In apparatus for raising and lowering the shelves of a cabinet, thecombination as set forth in claim 1 further characterized in that saidouter shell of said cabinet structure is provided with inwardlyextending rail members attached to the front edges of said side walls ofsaid outer shell, and the front edges of said side walls of said shelfstructure being provided with members slidable in grooves formed in saidrails to hold said side walls of said outer shell close to said sidewalls of said shelf structure.

3. In apparatus for raising and lowering the shelves of a cabinet, thecombination as set forth in claim 1 further characterized in that remotecontrol means in the form of a flexible cable is attached to said switchmeans for the remote actuation of said switch means.

4. In apparatus for raising and lowering the shelves of a cabinet, thecombination as set forth in claim 1 further characterized in that thereis provided a support in the top part of said cabinet above said shelfstructure for supporting said motor and said roller, and a limit switchconnected to said motor, said limit switch being adapted to be opened bysaid shelf structure when said shelf structure is raised to disconnectsaid motor and said brake means, and another limit switch connected tosaid brake means, said last mentioned limit switch being adapted to beopened when said shelf structure is down.

5. In apparatus for raising and lowering the shelves of a cabinet, thecombination as set forth in claim 1 further characterized in that saidbrake means comprises a wheel attached to the shaft of said motor, anelectromagnet and an armature associated with said electromagnet, aspring pressing said armature against said Wheel when said electromagnetis de-energized to prevent said motor shaft from turning, said armaturebeing pulled away from said wheel against the tension of said springwhen said electromagnet is energized to permit the shelf structure to belowered by gravity.

References Cited UNlTED STATES PATENTS JAMES T. MCCALL,

US. Cl. X.R.

Prinmry Examiner.

